Download - T11 geophysical testing-landschoot
GEOPHYSICAL TESTING FORSUBSURFACE INVESTIGATIONS
Speakers:Myron Hayden, Ph.D., P.E.
Matthew Monteith, E.I.MARCH 2013
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
PRESENTATION SUMMARY• GEOPHYSICAL TEST METHODS
• ELECTRICAL RESISTIVITY IMAGING (ERI)
WHAT IS ERI ENGINEERING APPLICATIONS OF ERI CASE STUDY: BOCA CHUBA SWMF
• GROUND PENETRATING RADAR (GPR)
WHAT IS GPR ENGINEERING APPLICATIONS OF GPR CASE STUDY: I-10 PAVEMENT SURVEY CASE STUDY: SR 26 (NEWBERRY ROAD) CASE STUDY: SR 10 (US 90) DEPRESSIONS
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
GEOPHYSICAL TEST METHODS• What is Geophysical Testing?
• “Geophysical Testing uses surface test methods to measure the physical properties and conditions of the subsurface material.”
• Measured Physical Properties:
• Seismic, Gravitational, Magnetic, Electrical, Electromagnetic;
• Geophysical Test Methods performed by EGS:
• Electrical Resistivity Imaging (ERI) – Electrical Properties
• Ground Penetrating Radar (GPR) – Electromagnetic Properties
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
ELECTRICAL RESISTIVITY IMAGING (ERI)• ERI is a geophysical test method performed from the ground surface and used to
generate 2-dimensional and 3-dimensional models of subsurface conditions.
ERI TEST EQUIPMENT AND DATA RECORDER ERI TRANSECT LINE
TESTING IN PROGRESS!
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
ENGINEERING APPLICATIONS OF ERI Cavity and Sinkhole Detection Geotechnical Site Characterization Groundwater Exploration Well Drawdown Studies Archaeological Site Investigation Detection of Contaminant Plumes Delineation of Organic Material Detection of Buried Debris Detection of Buried Utilities Underwater Tomography
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
BOCA CHUBA STORMWATER MANAGEMENT FACILITYCAPITAL CASCADES PARK
TALLAHASSEE / LEON COUNTY, FLORIDA
CASE STUDY:ELECTRICAL RESISTIVITY IMAGING (ERI) SURVEY
BACKGROUND INFORMATION
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
VIEW OF BOCA CHUBA SWMFVIEW OF RETAINING WALL
CLOSE-UP VIEW OF SIDEWALK SEPARATIONVIEW OF SIDEWALK SEPARATION BEHIND WALL
RESULTS OF ERI SURVEY
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
RESULTS OF ERI SURVEY
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
RESULTS OF ERI SURVEY
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
RESULTS OF ERI SURVEY
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
RESULTS OF ERI SURVEY
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
RESULTS OF ERI SURVEY
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
GROUND PENETRATING RADAR (GPR)• “GPR is a geophysical test method that transmits high frequency electromagnetic waves into
the ground that are reflected back due to changes in the electromagnetic potential of the subsurface materials.”
• GPR data is used to generate 2-dimensional and 3-dimensional models of subsurface conditions.
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
GPR SCANNING USING 250 MHz ANTENNA
GPR SCANNING USING 1.6 GHz ANTENNA GPR SCANNING USING 100 MHz ANTENNA
GROUND PENETRATING RADAR (GPR)
• Data collection occurs continuously and is displayed on a “real-time” display. This allows for preliminary field interpretation of results which is beneficial for time sensitive projects.
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
GPR SCANNING USING 250 MHz ANTENNA 2-D GPR PROFILE OBSERVED IN THE FIELDHOW GPR WORKS
ENGINEERING APPLICATIONS OF GPR
• Void Detection• Pavement Composition and Thickness• Utility Locations• Geotechnical Site Characterization• Karst Investigations• Detection of Buried Debris and Structures• Mapping Steel Reinforcement in Concrete• Unmarked Grave Locations
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
I-10 FROM WEST OF SR 95 TO EAST OF CR 95ARESURFACE, RESTORATION AND REHABILITATION
ESCAMBIA COUNTY, FLORIDA
CASE STUDY:GPR PAVEMENT SURVEY
PROJECT DESCRIPTION• Restoration, Rehabilitation, and Resurfacing of Major
Interchange along I-10
Mainline Roadway I-10
On and Off Ramps
• Determine Existing Pavement Characteristics;
Thickness and Layer Type
Asphalt, Base, Subgrade, and Embankment Materials
• Design New Pavement Section
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
MAINLINE ROADWAY I-10
PROJECT AERIAL VIEW
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
PROJECT CONCERNS• Field Safety during Pavement Coring
Poor Vertical Sight Distance
Poor Horizontal Sight Distance
Unsafe Lane Closure Conditions
Required Extensive MOT
Traffic Delays
• Unable to Core Single Lane Ramps
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
MAINLINE ROADWAY I-10
SINGLE LANE ON-RAMP TO I-10
GPR PROJECT APPROACH• Reduce the Quantity of Pavement Cores
• Conduct a GPR Survey to Determine Pavement Conditions
Three (3) Scans / Travel Lane
Scan at Highway Speeds
Highly Accurate GPS collecting location data
• BENEFIT:
Reduced Lane Closures – Improved Worker and Motorist Safety
Reduced Traffic Delays
Collection of Pavement Data Where It Was Not Possible To Core
Continuous Pavement Data
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
GPR SURVEY EQUIPMENT
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
GPR DATA
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
GPR DATA
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
GPR BENEFITS
• Identified Locations of Concrete Pavement
Reduced Damage to Milling Equipment
• Identified Pavement Characteristics at On and Off Ramps
• GPR Survey Conducted at Highway Speeds
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
SR 26 (NEWBERRY ROAD)RESURFACE, RESTORATION AND REHABILITATION
ALACHUA COUNTY, FLORIDA
CASE STUDY:GPR PAVEMENT SURVEY
PROJECT DESCRIPTION• Restoration, Rehabilitation, and Resurfacing of Major Roadway
• EGS’ ROLE:
Identify Cause(s) of Distress
Prepare Remediation Recommendations
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
MAINLINE ROADWAY SR 26 (NEWBERRY ROAD)MAINLINE ROADWAY SR 26 (NEWBERRY ROAD) DISTRESS
PROJECT AERIAL
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
END PROJECT
BEGIN PROJECT
AREA 1
AREA 2
GPR SURVEY EQUIPMENT
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
DISTRESSED AREA 1 GPR DATA
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
ASPHALT THICKNESS CONTOUR MAP
DISTRESSED AREA 1 GPR DATA
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
BASE THICKNESS CONTOUR MAP
DISTRESSED AREA 2 GPR DATA
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
ASPHALT THICKNESS CONTOUR MAP
DISTRESSED AREA 2 GPR DATA
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
BASE THICKNESS CONTOUR MAP
DISTRESSED AREA 2 GPR DATA
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
UTILITY PROFILE
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
SR 10 (US 90) BRIDGE APPROACH AND ROADWAY DEPRESSIONSRESURFACE, RESTORATION AND REHABILITATION
MADISON COUNTY, FLORIDA
CASE STUDY:GPR SURVEY
PROJECT DESCRIPTION• Restoration, Rehabilitation, and Resurfacing of Major Roadway
• EGS’ ROLE: Investigate Roadway Depressions
Identify Cause of Depressions
Prepare Remediation Recommendations
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
DEPRESSION AREA IN TRAVEL LANEBRIDGE OVER THE AUCILLA RIVER
PROJECT AERIAL
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
AREA 1
AREA 2
ROADWAY DEPRESSION
BRIDGE APPROACH DEPRESSIONS
BRIDGE APPROACH GPR DATA
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
ROADWAY DEPRESSION GPR DATA
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists
SUMMARY• GEOPHYSICAL TEST BENEFITS;
PROVIDES MORE DATA THAN TRADITIONAL METHODS; NON-DESTRUCTIVE TEST METHOD; REDUCED LANE CLOSURES AND TRAFFIC DISRUPTIONS; INCREASES PROJECT SPEED; INCREASES PROJECT ACCURACY; REDUCES PROJECT COSTS AND OVERRUNS;
• QUESTIONS?
ENVIRONMENTAL AND GEOTECHNICAL SPECIALISTSEngineers and Scientists